Process of treating biotite



ing books,

Patented Sept. 26, 1922.

UNITED STATES JAMES KEETH; OF SPOKANE, WASHINGTON.

PROCESS OF TREATING BIOTITE.

No Drawing.

To all 107mm it may concern:

Be it known that I, JAMES Knn'rrr, a citi zen of the United States,residing at Spokane, in Spokane County, and the State of Vashington.have invented certain new and useful Improvements in a Process ofTreating Biotite. of which the following is a specification.

My present invention relates to an improved process of treating biotiteor black mica one of the members of the group of mica minerals,characterized as a silicate of aluminum and iron with magnesium andpotassium forming component parts thereof.

By experiment, careful study, analysis, and practical application of thesteps of the following process, I have discovered and produced amaterial of especially high commercial value for purposes of electricand heat insulation, and because of its heat resisting qualities andlubrication may be used in packings for journals, etc., and in additionis readily adapted for decorative purposes when utilized with fancypaints, coating ornamental tiles, and also for coating wall papers.

The process as hereinafter described contemplates the hydration andcalcining of the raw material or ore as brought from the mine, and Ihave herein set forth one complete example of the physical embodiment ofmy invention which carries out the steps of my process according to thebest mode I have thus far devised for the practical application of theprinciples ,of my invention. The resulting finished product is welladapted for the uses above indicated and may be applied and employed inmany antll various other relations than those specifiec.

In mining the raw material, the mineral is found deposited in sheets orlayers formthe layers possessing a smooth somewhat greasy appearance, ofa dark brownish color, and possessing approximately the specific gravityof ordinary rock. The books of biotite as thus mined are in the form oflumps of mineral-of various sizes and constituted by laminations orclosely adhering sheets or leaves, and these lumps or books assumevarious shapes or forms, some thin and fiat with irregular outlines. andothers of greater thickness and more regular in outline, but allpossessing the characteristic of laminated adhering sheets or leaves.

The raw material thus mined in subjected Application filed April 12,1921. Serial No. 460,827.

to the process of dehydrating and burning under heat ranging throughvarious degrees depending upon the requirements of the resultingproduct.

As an exemplification of the process of treating the mineral, I take thebooks of biotite as above described and place them in a heating furnace.suitable equipped for the purpose, the quantity of raw materialdepending upon the size of the furnace. The intensity of the heat towhich the material is thus subjected may be varied for producingdifferent characteristics in the resulting product. I have found that bysubjecting the material to approximately a heat of 350 degrees F., thedehydrated and burnt material is increased or expanded in size,

i. e., the books or lumps of material retain their original individualbody formations as integral elements. but the size is increased and theform or shape may vary from the original. The product thus attainedretains its laminated or sheet formation. its specific gravity isdecreased and its color ischanged to a shiny light brown or bronzeshade.

By increasing the temperature of the heat in the furnace to say sevenhundred degrees F. and permitting the application of this heat toapproximately a period of seven minutes time. the size of the product isexpanded and closely approaches ten times the original size. Thus forexample I take a mass of lumps in quantity and size approximating acubic foot and weighing about 100 lbs. After subjecting these lumps to atemperature of 700' degrees F. for a period of about seven minutes, thecubical,

size of the mass has expanded to ten times the original size, and ofcourse each individual lump has been expanded approximately ten timesits original size. The specific gravity of the material has been greatlyreduced, and the resulting mass is made up of lofty constituents stillretaining their laminated form and although of increased size yetmaintaining somewhat a resemblance to the original shape. The individualpieces may be compared in weight to a similar size piece of cork. Thecolor has been further changed from that resulting when the material issubjected to a les intense heat as above described, and now possesses agold bronze shade or hue of much lighter appearance than the materialwhen-subjected to a less heat. The ex:

absorbent of water. Its brittleness or fragility renders it easy andfacile in pulverization, and the mass of lumps may thus be ground to afine flaky powder. And in the process of treating the material, thisstep of pulverizing or comminuting the lumps into powder is utilized inorder that the resulting powder may be incorporated as a pigment inpaints for decorative purposes. Thus the raw material is burnt,expanded,

and powdered and in this condition is readily" adaptable for thecommercial uses-above described.

Before comminuting the lofted lumps thus produced, they may be utilizedas filling material for difierent purposes, .thus

providing a light, resilient, lumpy mass suitable for packing or fillingpurposes. The powdered or comminuted burnt biotite may be incorporated,if desired with other components, and used in the electrical industry,where an insulating, non-inflammable, resistant material is necessaryand the composition ma be fashioned into sheets, washers,

tubes an other electrical fittings and appliances. Or the powdered-burntbiotite may be used as a powder in various commercial forms where suchan element is required, and in addition the powder may be used fordecoration in wall papers, ornamental tiles, &c. Because of its heatresisting qualities the burnt and expanded biotite may be adapted andfashioned as packings for journal boxes of railway cars or used as afiller in pipe and boiler coverings, and the powdered biotite may beused in fire proof and paint coverings.

Having thus fully described my invention, what I claim and desire tosecure by Letters Patent is The process of treating biotite whichconsists in subjecting the books to approx-' imately a temperature of700 F. whereby the books are dehydrated and lofted, and

subsequently comminuting the dehydrated and lofted books.

In testimony whereof I afiix my signature.

JAMES KEETH.

